Heretofore, there have been developed a variety of styrene derivatives for synthesis of functional polymers. For example, cyanostyrene and aminostyrene are easily made into polymers having various functional groups by radical polymerization.
On the other hand, there are known chlorostyrene, bromostyrene, chloromethylstyrene, and p-(2-bromoethyl)styrene as the styrene derivative having a halogen atom. Also, there is known bis-(1,2-dihalogenoethyl)benzene formed by attaching four halogen atoms to the two vinyl groups of divinylbenzene.